1. Filed of the Invention
The present invention relates to a metal-core substrate having an insulating layer thereon and a circuit pattern on the insulating layer and relates to an apparatus utilizing the same.
2. Description of the Related Art
A vehicle has several loads such as lamps and motors. In order to control these loads, heat-generating devices such as FET (Field-Effect Transistor) are utilized and it is necessary to heat sink these devices. In order to solve the problem, the heat-generating devices and heat sink members are mounted together to a substrate or a metal plate is placed inside a substrate as described in JP,2003-101177,A.
FIG. 9 shows a conventional substrate having a heat sink member. FIG. 10 shows a conventional substrate having a metal plate for heat sink.
As shown in FIG. 9, a conductive circuit pattern 912 is formed on an insulating substrate 911. The substrate 911 has a heat-generating device 92 such as FET to control the loads of a vehicle, a driving part 93 to drive the heat-generating device 92, a heat sink member 95, for example a fin, to heat sink the heat-generating device 92, and a male connector 944 receiving a plurality of male terminals 914. A battery (not shown) supplies an electric power to the loads (not shown) through female terminals 514, the male terminals 514, and the FET. The substrate 911 having these parts is received in a box-shaped case 94.
In FIG. 9, the female connector 544 has the plurality of female terminals 514 connected to electric wires 5 and is fitted into the male connector 944 in a direction shown by an arrow. The electric wires 5 are connected to the loads such as battery, lamps and motors. Thus, the female terminals 514 provide the electric power to the male terminals 914 and receive the electric power to supply to the loads from switching controls such as the FET.
FIG. 10 shows a conventional substrate 91 having a metal plate 913 to increase a mechanical strength thereof and to heat sink a heat-generating device 92 without a heat sink member 95 such as a fin. The metal-core substrate 91 has the metal plate 913 and an insulating layer 911 covering the metal plate 913. A circuit pattern 912 is formed on the insulting layer 911. The elimination of the heat sink member reduces a number of parts and provides a space so that the metal-core substrate can be minimized. The other structures of FIG. 10 are the same as those of FIG. 9 and the explanations are omitted.
Recently, small and thin sized substrates are required. JP,2004-303576,A discloses that male terminals 914 are formed on a substrate as a circuit pattern. However, since the male terminals 914 connected to a battery and loads are subjected to a high current of order of amperes, it is necessary to have a certain level of thickness. Accordingly, the male terminals 914 are not suitable to be formed as the circuit pattern. The large size of the male terminals 914 and connectors 944 receiving the male terminals 914 prevent the substrate from being smaller and thinner.